Method and apparatus for avoiding ribbon windings when winding a cross-wound bobbin

Abstract

The method and apparatus avoids ribbon windings when winding a cross-wound bobbin or cheese being driven by a drive drum having reversing thread grooves for yarn guidance and a drive mechanism having a course of motion. The circumferential speed of the drive drum is continuously varied. The cheese is accelerating and decelerating exclusively with the drive drum. The drive drum is accelerated and braked with the drive mechanism of the drive drum in accordance with a predeterminable periodic function. The cheese is rotated with a course of motion following the course of motion of the drive drum in a permanently phase-displaced manner.

I claim: 
     
       1. Method for avoiding ribbon windings when winding a cross-wound bobbin or cheese being driven by a drive drum having reversing thread grooves for yarn guidance and a drive mechanism having a course of motion, which comprises continuously varying the circumferential speed of the drive drum; accelerating and decelerating the cheese exclusively with the drive drum; accelerating and braking the drive drum with the drive mechanism of the drive drum in accordance with a predeterminable periodic function; and rotating the cheese with a course of motion following the course of motion of the drive drum in a permanently phase-displaced manner. 
     
     
       2. Method according to claim 1, which comprises setting the predeterminable periodic function as a sine function. 
     
     
       3. Method according to claim 1, which comprises driving the drive drum and the cheese with substantially the same average circumferential speeds. 
     
     
       4. Method according to claim 1, which comprises continuously measuring the bobbin diameter of the cheese, and varying at least one of the frequency and the amplitude of the periodic function of the variation in circumferential speed of the drive drum without exceeding a predeterminable value of the phase displacement. 
     
     
       5. Method according to claim 1, which comprises ascertaining the diameter of the cheese varying during the production of the cheese from the ratio between the average angular speeds of the cheese and drive drum at any given time. 
     
     
       6. Method according to claim 1, which comprises increasing at least one of the amplitude and the frequency of the periodic function of the variation in circumferential speed of the drive drum in known primary ribbon zone critical regions in which ribbon windings occur. 
     
     
       7. Apparatus for avoiding ribbon windings when winding a cross-wound bobbin or cheese, comprising a drive drum for driving the cheese having reversing thread grooves for yarn guidance, and a drive mechanism having means for accelerating and braking said drive drum and means for continuously varying the circumferential speed of said drive drum. 
     
     
       8. Apparatus according to claim 7, wherein said drive mechanism includes an electric motor controllable in fourquadrant operation. 
     
     
       9. Apparatus according to claim 7, including an intermediate circuit into which brake energy arising in a braking phase is fed. 
     
     
       10. Apparatus according to claim 7, wherein said drive mechanism includes an electric motor being operated with multi-phase alternating current and having a characteristic slip curve suitable for arising acceleration moments 
     
     
       11. Apparatus according to claim 7, wherein said drive mechanism includes an electric motor, and a variable speed gear disposed between said electric motor and said drive drum. 
     
     
       12. Apparatus according to claim 7, including measured value pickups for detecting the instantaneous angular speed of said drive drum and the cheese, a computer for ascertaining the diameter of the cheese from the ratio of average values of the angular speeds, an operative connection between said computer and said measured value pickups, and a command connection between said computer and said drive mechanism having means for controlling at least one of the amplitude and the frequency of said drive mechanism as a function of the ascertained diameter. 
     
     
       13. Apparatus according to claim 7, including a creel, a measured value pickup disposed on said creel for detecting the angular position of said creel proportional to the bobbin diameter, and a command connection between said measured value pickup and said drive mechanism for controlling at least one of the amplitude and the frequency of the periodic function of the variation in circumferential speed of said drive drum. 
     
     
       14. Apparatus according to claim 12, wherein said computer includes means for controlling said drive mechanism through said command connection for increasing at least one of the amplitude and the frequency of the periodic function of the variation in circumferential speed of the drive drum at times, upon reaching primary ribbon zones recognized from the ascertained diameter of the cheese. 
     
     
       15. Apparatus according to claim 13, wherein said computer includes means for controlling said drive mechanism through said command connection for increasing at least one of the amplitude and the frequency of the periodic function of the variation in circumferential speed of the drive drum at times, upon reaching primary ribbon zones recognized from the ascertained diameter of the cheese. 
     
     
       16. Apparatus according to claim 13, wherein said drive mechanism includes an electric motor, and a hysteresis clutch disposed between said electric motor and said drive drum for controlling the amplitude of the periodic function of the variation in circumferential speed of said drive drum. 
     
     
       17. Apparatus according to claim 14, wherein said drive mechanism includes an electric motor, and a hysteresis clutch disposed between said electric motor and said drive drum for controlling the amplitude of the periodic function of the variation in circumferential speed of said drive drum. 
     
     
       18. Apparatus according to claim 15 wherein said drive mechanism includes an electric motor, and a hysteresis clutch disposed between said electric motor and said drive drum for controlling the amplitude of the periodic function of the variation in circumferential speed of said drive drum. 
     
     
       19. Apparatus for avoiding ribbon windings when winding a cross-wound bobbin or cheese, comprising a drive drum for exclusively accelerating and decelerating the cheese, said drive drum having reversing thread grooves for yarn guidance, and a drive mechanism having means for continuously varying the circumferential speed of the drive drum, means for accelerating and braking the drive drum according to a course of motion having a predeterminable periodic function, and means for rotating the cheese with a course of motion following the course of motion of the drive drum in a permanently phase-displaced manner.